do not use fixed DNS on windows

configure.ac

@@ -29,13 +29,9 @@ LT_INIT(win32-dll disable-static)
 dnl Workaround for mingw, whose compiler doesn't check in /usr/include ...
 case "$target_os" in
 	*mingw*)
-		if test "$cross_compiling" = "yes"; then
-			CPPFLAGS="$CPPFLAGS -DUSE_FIXED_NAMESERVERS"
-		else
-			if test "$prefix" = "/usr" ; then
-				CPPFLAGS="$CPPFLAGS -I/usr/include"
-				LDFLAGS="$LDFLAGS -L/usr/lib"
-			fi
+		if test "$prefix" = "/usr" ; then
+			CPPFLAGS="$CPPFLAGS -I/usr/include"
+			LDFLAGS="$LDFLAGS -L/usr/lib"
 		fi
 	;;
 esac